Mathematical Modelling Of Wreck Events Originated By Dam Collapse

Based on Saint-Venant (shallow water) equations, in this paper the mathematical model of wreck events produced by dam collapse is constructed. A two-layer difference scheme with non-linear regularisation is used for the numerical solution of the aforementioned model. The convergence of this difference scheme in Eulerian variables with non-linear regularisation to the smooth solutions of one-dimensional Saint-Venant equations are considered for a Cauchy problem with periodic (in spatial variables) solutions. The proof of difference scheme convergence is conducted using the energetic method. The existence and uniqueness of the difference scheme solution is proved. That the difference scheme converges in mesh norm $L_2$ with speed $O\lpar h^2\rpar$ in the class of sufficiently smooth solutions of the difference scheme is also proved.     

关于二元等重码的最大码字数

本文利用Johnson Schemes理论研究了二元等重码及其最大码字数问题.在Delsarte的associate schemes理论中,Q-变换被引入以研究二元等重码的距离分布.首先,本文研究了等重码距离分布的Q-变换;然后,通过使用Q-变换的性质,我们研究了二元等重码的最大码字数问题并得到码字数的一个新的上界,该上界在形式上类似于纠错码理论中的Grey-Rankin界,并且在某些情况下优于已知的结果.     

Knowledge engineering concepts for decision support system design and implementation

The design of computer-based systems that simulate expert human consulting by drawing on large amounts of task-specific knowledge has been a major research activity of applied artificial intelligence over the last ten years. Building decision support systems that incorporate aspects of this research is a promising new field. The purpose of this paper is to discuss concepts of “knowledge engineering” that are most relevant in designing and building knowledge-based decision support systems.     

Analysis of playout strategies for voice transmission using packet switching techniques

Due to variations in network delay, a stream of voice packets with deterministic interarrival times to a data network may not have deterministic interdeparture times at the destination. Two playout schemes which are designed to remove such variations in delay are considered. Analytic results for the performance of these two schemes are obtained. Numerical examples showing the effect of coefficient of variation of interdeparture time on performance are presented.     

田湾核电厂址事故后果评价中天气取样方案的比较研究

本文基于田湾核电厂址1998年9月1日至1999年8月31日一整年的逐时气象数据、SF6实测扩散参数和评价区(40km×40km)各网格(2km×2km)人口分布等实测资料,对依据秦山、田湾核电厂址和惠安拟选核电厂址多年逐时气象数据统计分析后提出的五个天气取样候选方案,估算了某假想事故在评价区内造成的集体剂量,得到事故集体剂量余补累积概率分布函数(即CCFD曲线)。同时应用整年“逐时滑移”事故释放起始时刻方法计算了事故集体剂量的CCFD曲线,即“标准”CCFD曲线,并将五类天气取样候选方案获得的95%累积概率水平事故集体剂量值与由“标准”CCFD曲线得到的相应值作比较。结果表明,天气取样候选方案四最佳,此方案给出的95%累积概率水平事故集体剂量与由“标准”CCFD曲线得到的相应值的相对偏差仅为3%。     

APPLICATION OF INVERSE TRANSFORMATION TECHNIQUE TO 3-PHASE POLE-CHANGING WINDINGS

ABSTRACT

The inverse d-q transformation is used to develop pole-changing 3-phase induction motors from change-pole 2-phase ones. Transformation procedures, common features of the original 2-phase and derived 3-phase windings, basic differences between derived and conventional 3-phase windings together with their limitations are discussed in detail. Single winding change pole arrangements for 3-phase machines are derived from 2-phase ones. In addition, a mathematical model is presented to take satisfactorily into account the effects of unbalanced impedances and multi harmonic interactions. Tests conducted both in 2 and 3-phase operations on a 10/6 change-pole machine are reported. The nature of agreement between the computed and experimental results validates the transformation technique and also the mathematical model used in the process.     

机械产品概念设计方案生成技术研究及软件系统开发

概念设计方案生成被认为是产品概念设计中最为关键的技术。它是决定产品最终质量、市场竞争力以及企业获利最为重要的因素。本文基于公理化设计 (AxiomaticDesign)理论 ,讨论了机械产品概念设计方案生成的关键技术和实现策略 ,并介绍了相应的软件系统开发     

一种新的彩色可视秘密共享方案

提出了一种基于线性方程组求解的彩色可视秘密共享方案。该方案把一幅图像秘密地分成n幅共享图像,使得任意k个或更多的共享能够恢复秘密图像,而任意少于k个共享却得不到有关原始图像的任意信息。另外,每个共享图像与原始图像有着同样大小,而且恢复图像和秘密图像完全一样,没有任何失真。所以它是一种理想、完备的（k,n）门限方案,适用于把黑白、灰度、彩色图像作为秘密进行共享。     

三角网格细分模式的统一框架研究

通常情况下,三角网格细分模式由面分裂的初始模式和点分裂的对偶模式构成。本文为这两种不同的模式提出了一个统一的框架,定义了复合细分操作,并对当前流行的几种模式进行了分析。在此框架基础上,三角网格细分模式得以扩展。